Crocking is a transfer of color from the surface of a colored fabric to an adjacent area of the same fabric or to another surface principally by rubbing action. Crockfastness is color fastness to rubbing (crocking). The improvement of crockfastness/colorfastness of dyed textile fabrics has been an ongoing problem in the textile industry. Attempts to resolve the problem have entailed additives during the dyeing process as well as post treatments.
For example, U.S. Pat. No. 4,531,946 discloses use of a fabric finish containing a reactive polyamine derivative in combination with a blocked urethane for cellulosic and cellulosic blends which have been dyed with disperse/naphthol or disperse/sulfur disperse/vat dye systems. U.S. Pat. No. 4,737,156 discloses use of cationic cellulose graft copolymers for improving dye fastness to a dyed textile substrate by post dye application (top-up). U.S. Pat. No. 4,740,214 discloses a pattern dyeing process wherein an anionic and a cationic component come into contact with each other when a dye solution is applied to a textile. An ionic interaction is stated to occur to form a water-insoluble dye-impermeable skin around individual dye droplets which then controls undesired migration of the dye. One of the components is applied to a textile material prior to application of the dye solution in a desired pattern and then the corresponding counter-ionic material is applied as a component of the dye solution.
Glyoxylated polyacrylamide-diallyldimethyl ammonium chloride copolymer (GPA) resins are known for use as dry strength and temporary wet strength resins for paper. U.S. Pat. No. 4,605,702, for instance, teaches the preparation of a wet strength additive by glyoxalating an acrylamide copolymer having a molecular weight from about 500 to 6000. The resulting resins have limited stability in aqueous solution and gel after short storage periods even at non-elevated temperatures. Accordingly, the resins are typically supplied in the form of relatively dilute aqueous solutions containing only about 5-10 wt % resin.
Aminopolyamide-epichlorohydrin (APAE) resins have been used as wet strength additives for paper. U.S. Pat. No. 3,311,594, discloses the preparation of APAE wet strength resins. The resins are prepared by reacting epichlorohydrin with aminopolyamides, sometimes referred to as polyaminoamides, or polyaminourylenes containing secondary amino hydrogens. The APAE resins can also exhibit storage problems in concentrated form and gel during storage, although generally to a lesser extent than the GPA resins. As such, it has been common practice to dilute the APAE resins to low solids levels to minimize gelation. The APAE resins also are known to impart dry strength to paper, but the vast increase in wet strength which results simultaneously has made APAE resins unsuitable for use as dry strength resins in the preparation of recyclable paper.
U.S. Pat. No. 5,674,362 discloses a method for improving the strength of recycled paper by adding a mixed resin solution of APAE resin and GPA resin to the wet end of the paper-making process. The use of the mixed APAE:GPA resin solution produces paper which exhibits significantly increased dry strength performance as compared to the joint use of the resins individually.
It is an object of this invention to provide a method for improving the color retention and crocking of a dyed textile product.